There is a need for forming small structures in semiconductors in a robust and repeatable manner. However, to form small pixels is very challenging using standard semiconductor processing techniques. This is exacerbated if there are topographical features which leads to complications in processing, even when using high resolution lithography tools. Also, additional thermal processing is known to impact on the efficiency of emissive devices such as LEDs, RCLEDs, VCSELs, etc. Thus, the ability to form electrically modified and conductive regions in one thermal processing step is an added benefit.
The ability to form structures by channeling a current into a p-n junction with reduced electrical leakage is important but becomes even more acute for smaller pixels owing to the increase in contact resistance related to the small contact area. Hence there is a need to effectively reduce current leakage.
The ability to form structures with an emission profile which is non-uniform (e.g. linear) can be a desirable feature. As an example, LED pixels fabricated to have a Gaussian type profile, retain a Gaussian intensity profile when coupled to optical elements i.e. lenses.
The present invention also provides the ability to eliminate passivation with oxide by use of converted p-GaN with modified electrical properties.
It is an object of at least one aspect of the present invention to obviate or mitigate at least one or more of the aforementioned problems.
It is a further object of at least one aspect of the present invention to provide a process for forming small pixels on semiconductors with reduced current leakage.
It is a further object of at least one aspect of the present invention to provide a process for forming pixels with a nonlinear beam profile.
It is a further object of at least one aspect of the present invention to eliminate and/or reduce the need for passivation and to simplify device processing.
It should be noted that for any of the objects of the present invention they may be treated as an inclusive “or”. As an example, a condition A (small pixel) or B (nonlinear emission profile) is satisfied by any one of the following: A is present and B is not present, A is not present and B is present and both A and B are present.